An ion beam angle calibration and emittance measurement system, comprising a plate comprising an elongated slit therein, wherein the elongated slit positioned at a rotation center of the plate and configured to allow a first beam portion to pass therethrough. A beam current detector located downstream of the plate, wherein the beam current detector comprises a slit therein configured to permit a second beam portion of the first beam portion to pass therethrough, wherein the beam current detector is configured to measure a first beam current associated with the first beam portion. A beam angle detector is located downstream of the beam current detector and configured to detect a second beam current associated with the second beam portion. The plate, the current beam detector and the beam angle detector are configured to collectively rotate about the rotation center of the plate.